"Stain coating" means a non-protective coating containing dye or pigment which is applied to a substrate to impart color without obscuring the grain of the substrate, i.e., the appearance and texture of the surface of the substrate due to its physical structure, or for a transparent substrate, without blocking the passage of light through the substrate.
Ill. Admin. Code tit. 35, § 211.6250
Added at 18 Ill. Reg. 1253, effective January 18, 1994